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How to construct a timedelta object from a simple string
...uld parse using regular expressions
Here is re-based solution:
import re
from datetime import timedelta
regex = re.compile(r'((?P<hours>\d+?)hr)?((?P<minutes>\d+?)m)?((?P<seconds>\d+?)s)?')
def parse_time(time_str):
parts = regex.match(time_str)
if not parts:
...
What is dynamic programming? [closed]
...imal sub-structure (e.g., every subset of any path along the shortest path from A to B is itself the shortest path between the 2 endpoints assuming a distance metric that observes the triangle inequality).
– Shea
Jun 30 '09 at 19:56
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What are the mathematical/computational principles behind this game?
... same).
Every two lines meet in exactly one point (this is a bit different from Euclid).
Now, add "finite" into the soup and you have the question:
Can we have a geometry with just 2 points? With 3 points? With 4? With 7?
There are still open questions regarding this problem but we do know this:...
Django: Get model from string?
...pplication loading system.
-- Scott Woodall
Found it. It's defined here:
from django.db.models.loading import get_model
Defined as:
def get_model(self, app_label, model_name, seed_cache=True):
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What can I do with a moved-from object?
...ndard define precisely what I can do with an object once it has been moved from? I used to think that all you can do with a moved-from object is do destruct it, but that would not be sufficient.
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Removing an element from an Array (Java) [duplicate]
Is there any fast (and nice looking) way to remove an element from an array in Java?
15 Answers
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Extract directory from path
..."stuff/backup/file.zip" . I need a way to get the string " stuff/backup/ " from the variable $file .
5 Answers
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Throwing exceptions from constructors
I'm having a debate with a co-worker about throwing exceptions from constructors, and thought I would like some feedback.
1...
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...standard method, but also includes older methods and various other methods from answers to similar questions scattered around this site.
tmp <- data.frame(x=gl(2,3, labels=letters[24:25]),
y=gl(3,1,6, labels=letters[1:3]),
z=c(1,2,3,3,3,2))
Using the tidyve...
How does JPA orphanRemoval=true differ from the ON DELETE CASCADE DML clause
...hing. It marks "child" entity to be removed when it's no longer referenced from the "parent" entity, e.g. when you remove the child entity from the corresponding collection of the parent entity.
ON DELETE CASCADE is a database-specific thing, it deletes the "child" row in the database when the "par...